Testing the Addition of Copanlisib to Eribulin in Metastatic Triple Negative Breast Cancer

This phase I/II trial studies the side effects and best dose of copanlisib and how well it works when given together with eribulin in treating patients with triple negative breast cancer that has spread from where it first started (primary site) to other places in the body (metastatic). Copanlisib may stop the growth of tumor cells by blocking some of the enzymes needed for cell growth. Chemotherapy drugs, such as eribulin, work in different ways to stop the growth of tumor cells, either by killing the cells, by stopping them from dividing, or by stopping them from spreading. Giving copanlisib and eribulin together may work better in treating advanced stage triple negative breast cancer compared to eribulin alone.